Total BS. Rosenstein was threatened by Nunes and simply laid out the facts:

Renato Mariotti
‏@renato_mariotti

Staffers for Devin Nunes apparently threatened to hold Rod Rosenstein in Contempt of Congress in a recent meeting. He told them if they did, he would have the right to subpoena their communications and put them on the witness stand to prove them wrong. He's 100% right about that.

Prove them wrong about what? They have authority over Rosenstein. He answers to Congress, not the other way around.